Except as otherwise noted, a file may be specified by a name
(such as <'sub\abc.q')or by an integer
file number obtained from open(1!:21 <'sub\abc.q').

1!:0 y

Directory. y is a string of the path
search expression (a boxed string is also accepted);
the result is a 5-column table of the file name,
modification time, size, permission, and attributes,
individually boxed. For example, try 1!:0 '*.*'.
The permission and attribute columns are system dependent.
For example, in Windows: